| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
,
* Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil;
Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto-USP, Ribeirão Preto, Brazil;
Fundação Zerbini, São Paulo, Brazil; and
LIM-60, Division of Allergy and Clinical Immunology, São Paulo University Medical School, São Paulo, Brazil
Recent studies have revealed an important role for CTLA-4 as a negative regulator of T cell activation. In the present study, we evaluated the importance of CTLA-4 to the immune response against the intracellular protozoan, Trypanosoma cruzi, the causative agent of Chagas’ disease. We observed that the expression of CTLA-4 in spleen cells from naive mice cultured in the presence of live trypomastigote forms of T. cruzi increases over time of exposure. Furthermore, spleen cells harvested from recently infected mice showed a significant increase in the expression of CTLA-4 when compared with spleen cells from noninfected mice. Blockage of CTLA-4 in vitro and/or in vivo did not restore the lymphoproliferative response decreased during the acute phase of infection, but it resulted in a significant increase of NO production in vivo and in vitro. Moreover, the production of IFN-
in response to parasite Ags was significantly increased in spleen cells from anti-CTLA-4-treated infected mice when compared with the production found in cells from IgG-treated infected mice. CTLA-4 blockade in vivo also resulted in increased resistance to infection with the Y and Colombian strains of T. cruzi. Taken together these results indicate that CTLA-4 engagement is implicated in the modulation of the immune response against T. cruzi by acting in the mechanisms that control IFN- and NO production during the acute phase of the infection.
This article has been cited by other articles:
|
|
 |
|
  M. D. Taylor, A. Harris, S. A. Babayan, O. Bain, A. Culshaw, J. E. Allen, and R. M. Maizels CTLA-4 and CD4+CD25+ Regulatory T Cells Inhibit Protective Immunity to Filarial Parasites In Vivo J. Immunol., October 1, 2007; 179(7): 4626 - 4634. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. E. A. Souza, M. O. C. Rocha, C. A. S. Menezes, J. S. Coelho, A. C. L. Chaves, K. J. Gollob, and W. O. Dutra Trypanosoma cruzi Infection Induces Differential Modulation of Costimulatory Molecules and Cytokines by Monocytes and T Cells from Patients with Indeterminate and Cardiac Chagas' Disease Infect. Immun., April 1, 2007; 75(4): 1886 - 1894. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
